Q: Can you paint over a facade treated with järnvitriol?This article, plus Olle's research, gave me a bit more hope about successfully being able to paint our house after all.
A: Yes, slamfärg or solvent-based paints work.
The real kicker came a few days later, when we met up with old friends Lotta and Jan-Erik, who coincidentally enough, live a few islands over, and are good friends with Annika and Olle.
Jan-Erik is a man of much experience and many friends in the archipelago, and he gave me the name of a friend who is the MD of a paint company who might be able to give me advice. When I got back to Texas, I sent an email with a few photos attached, asking for advice. Within 24 hours, I received the following reply:
1. It is always best to keep using the same product that was used from the beginning or in your case do nothing and accept the look of the faces.One of the things that gave us pause about slamfärg was that it was a bit transparent, so covering our spots might be a problem, especially if we went for a lighter shade. It also can be a bit chalky, and requiring more frequent touch-ups.
2. It could be possible to paint the faces with a linseed oil based paint. Then you would have to repaint the southern face every 10-15 years. We don’t have any experiences of painting on sprayed surfaces [I told him we used a sprayer to apply the järnvitriol] so we can’t guarantee the result. But you could test this on your southern face.
But linseed oil paint? That's worth looking into. And we will, in part 3!